August, 1945 



Carter: Wetwood of Elms 



413 



Fig. 10. — Callus formation that developed 

 over a crack in the trunk of a wetwood-affect- 

 ed elm. The crack developed during the 

 previous winter and flux became apparent 

 during the spring and early summer. 



to show cracks. He observed that the sap 

 from wetwood prevented callusing. 



Root Pathology 



Roots of affected trees usually show 

 very little discoloration. However, in seed- 



Fig. 11. — Split stump of a wetwood-affected 

 Moline elm. Wetwood does not, as a rule, 

 spreail into roots of grafted elms but is con- 

 fined mainly to the heartwood of the trunk. 



Fig. 12. — Sections of an elm branch that 

 wilted because of wetwood. Grayish brown 

 streaks form in the current-season wood, 

 principally in the spring wood. When freshly 

 cut, the discolored wood appears to be water- 

 soaked. 



